108 SYLVICULTURE IN THE TROPICS K . u 



e.g. with pyramidal, rounded, or flat or umbrella-shaped 

 crowns. Cover is the action of the crown on the space 

 vertically under it. A plant vertically under the crown 

 of a tree is said to be under cover ; those not under 

 cover are said to be in the open. 



Plants which can exist under cover are called shade- 

 enduring, while those which can only thrive in the 

 open are called shade-avoiding such a plant, if it 

 gets under cover, will have its growth retarded ; it will, 

 in other words, become suppressed. In the struggle 

 for existence between component trees of a crop, those 

 which are left behind in the race for height are at first 

 dominated, and if they fall still more behind and come 

 under cover of other trees they become suppressed, 

 unless very shade-avoiding. Those which keep the lead 

 are dominant. 



A tree or crop becomes exploitable when it has 

 reached the most useful dimensions for the purpose for 

 which it is destined by the proprietor. To exploit a 

 forest is to fell it according to sylvicultural principles. 



The rotation of a crop is the period from the time 

 when its component trees have germinated to that 

 when they are felled. 



By advance- growth is meant the crop of seedlings 

 and saplings which have sprung up in a forest before 

 any regeneration fellings have been undertaken. 



A nurse is a tree or shrub intended to shelter 

 young plants until they are strong enough to live in the 

 open. 



A coupe is the area over which a felling is made. 



A high forest is a forest the component trees of 

 which are mostly sprung direct from seed, while a coppice 

 or copse is a wood or forest the trees of which are most 

 of them stool-shoots or root-suckers. A simple coppice 

 is one none of the trees of which are selected to stand 

 longer than one rotation, or where some are kept at the 

 most to last through a second rotation ; in a coppice- 

 under-standards or stored coppice, on the other hand, 

 certain trees called standards or stores are selected to 



